Submission #883829

#	Time	Username	Problem	Language	Result	Execution time	Memory
883829		MisterReaper	Palembang Bridges (APIO15_bridge)	C++17	100 / 100	224 ms	11628 KiB

bridge

#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

const i64 INF = 1E18;

char ch[2];
int x[2];

template <typename T>
ostream& operator<< (ostream &out, vector <T> vec) {
    out << "{";
    for(int i = 0; i < int(vec.size()); i++) {
        out << vec[i];
        if(i +1 < int(vec.size())) {
            out << ", ";
        }
    }

    return out << "}";
}

#define ONLINE_JUDGE

i64 suml = 0, sumr = 0;
multiset <int> low, up;

void balance() {
    while(int(low.size()) > int(up.size())) {
        int x = *low.rbegin();
        up.emplace(x);
        suml -= x;
        sumr += x;
        low.erase(low.find(x));
    }


    while(int(up.size()) > int(low.size())) {
        int x = *up.begin();
        low.emplace(x);
        suml += x;
        sumr -= x;
        up.erase(up.find(x));
    }
}

void add(int x) {
    low.emplace(x);
    suml += x;

    balance();
}

void solve() {
    int k, n;
    cin >> k >> n;

    i64 total = 0;
    vector <pair <int, int>> a;
    for(int i = 0; i < n; i++) {
        cin >> ch[0] >> x[0] >> ch[1] >> x[1];
        if(ch[0] != ch[1]) {
            a.emplace_back(x[0], x[1]);
        } else {
            total += abs(x[0] - x[1]);
        }
    }

    n = int(a.size());
    i64 ans = INF;

    sort(a.begin(), a.end(), [&](pair <int, int> a, pair <int, int> b) -> bool {
        return a.second + a.first < b.second + b.first;
    });

    vector <i64> pref(n +1);
    for(int i = 0; i < n; i++) {
        add(a[i].first);
        add(a[i].second);

        //cerr << a[i].first << " " << a[i].second << " :: " << sumr << " " << suml << "\n";
        pref[i +1] = sumr - suml;
    }

    ans = min(ans, pref[n]);

    if(k == 2) {
        low.clear();
        up.clear();
        suml = sumr = 0;

        for(int i = n; i >= 1; i--) {
            add(a[i -1].first);
            add(a[i -1].second);

            //cerr << a[i].first << " " << a[i].second << " :: " << sumr << " " << suml << " | " << pref[i -1] << "\n";
            ans = min(ans, pref[i -1] + sumr - suml);
        }
    }

    cout << ans + total + n;
}

signed main() {
    #ifndef ONLINE_JUDGE
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

    solve();

    return 0;
}

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37